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Journal of Materials Science & Technology 2022年第22期117卷 8-22页

作者： Young-Kyun Kim Kee-ahn Lee Department of Materials Science and Engineering Inha UniversityIncheon 22212Republic of Korea Korea Institute of Materials Science(KIMS) Changwon 51508Republic of Korea

High-entropy alloys(HEAs)with interstitial atoms that are produced by additive manufacturing have gained intensive interest in the materials science community because of their suitability for constructing high-strength net-shape ***,a strategy to additionally enhance the strength of selective laser melted carbon-containing HEAs was *** as-built carbon-containing HEAs(C_(x)(Cr_(20)Mn_(20)Fe_(20)Co_(20)Ni_(20))_(100-x)(x=0.5 at.%,1.0 at.%,and 1.5 at.%))contain supersaturated carbon,and the extent of supersaturation increases as the carbon content *** subjected to aging treatment at 650°C for 1 h,the microstructure of the three alloys did not change at the grain ***,the microstructure at the sub-grain scale changed markedly,and these changes influenced the tensile properties and deformation *** particular,the tensile strength of aged 1.5C-HEA at 650°C was∼1.2 GPa at room temperature,which is higher than those reported for CrMnFeCoNi ***,the main deformation mechanism changed from deformation twinning to dislocation-mediated slip,resulting in much higher strain hardening capacity after the aging *** work led to the development of an alternative promising method that involves tailoring the microstructure,to enhance the mechanical properties of additively manufactured metallic materials that contain interstitial atoms.

关键词： Selective laser melting High-entropy alloy Carbon contents Aging Microstructure evolution Tensile property Deformation mechanism

Chaos Synchronization of Nonlinear Bloch Equations Based on Input-to-State Stable Control

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Communications in Theoretical Physics 2010年第2期53卷 308-312页

作者： Choon Ki ahn Faculty of the Division of Electronics and Control Engineering Wonkwang University

In this paper, we propose a new input-to-state stable （ISS） synchronization method for chaotic behavior in nonlinear Bloch equations with external disturbance. Based on Lyapunov theory and linear matrix inequality （LMI） approach, for the first time, the ISS synchronization controller is presented to not only guarantee the asymptotic synchronization but also achieve the bounded synchronization error for any bounded disturbance. The proposed controller can be obtained by solving a convex optimization problem represented by the LMI. Simulation study is presented to demonstrate the effectiveness of the proposed synchronization scheme.

关键词： chaos synchronization input-to-state stable (ISS) control nonlinear Bloch equations linear matrix inequality (LMI) Lyapunov theory

Pathologic etiology and predictors of malignancy in children with cervical lymphadenopathy

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World Journal of Pediatrics 2023年第3期19卷 283-287页

作者： Jee Woo Kim Jee Yeon Baek Ji Young Lee Sung Min Lim Ji-Man Kang Won Kee ahn Seung Min Hahn Jung Woo Han Chuh Joo Lyu jong Gyun ahn Department of Pediatrics Severance Children's HospitalYonsei University College of Medicine50-1 Yonsei-RoSeodaemun-guSeoul 03722South Korea Institute for Immunology and Immunological Diseases Yonsei University College of MedicineSeoulSouth Korea Division of Pediatric Hematology and Oncology Department of PediatricsYonsei University College of MedicineYonsei University Health SystemSeoulSouth Korea Department of Pediatric Hemato-Oncology Yonsei Cancer CenterYonsei University Health SystemSeoulSouth Korea

Cervical lymphadenopathy in children is a common disease entity that is accompanied by a variety of processes,ranging from benign disease to *** the cause of cer-vical lymphadenopathy in children is often benign[1-4],the presence of enlarged lymph nodes can cause anxiety to parents because of its association with *** should be considered for the histologic diagnosis of persistent or unex-plained cervical lymphadenopathy in ***,biopsy is an invasive examination method,and it is difficult to clinically determine whether biopsy is needed in children with unexplained cervical ***,clini-cians should be aware of the differential diagnosis of lymph node enlargement in children and should identify situations in which malignancy may be *** this study,we aimed to identify the etiology of pediatric cervical lymphadenopathy using biopsy and to analyze the risk factors associated with malignancy in children with cervical lymphadenopathy.

关键词： malignancy cervical diagnosis

Increased expression of the nitric oxide synthase gene and protein in corpus cavernosum by repeated dosing of udenafil in a rat model of chemical diabetogenesis

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Asian Journal of Andrology 2009年第4期11卷 435-442页

作者： GJ ahn HK Chung CH Lee KK Kang BO ahn Research Laboratory Dong-A Pharmaceutical Company Kiheung Yongin Kyunggi 446-905 Korea

Erectile dysfunction （ED） is a major complication of diabetes mellitus （DM）. This study investigates the relationship between ED and the downregulation of constitutive nitric oxide synthase （cNOS） in the corpus cavernosum （CC） of diabetic rats. It also examines the effects of udenafil, a phosphodiesterase type 5 （PDE5） inhibitor, on ED and cNOS expression levels. After 16 weeks of daily oral treatment with udenafil in diabetic rats, the intracavernous pressure/mean arterial pressure （ICP/MAP） ratio was recorded to measure erectile function, and cNOS expression was measured using reverse transcriptase （RT）-PCR and immunoblots. Although the ICP/ MAP ratio and the expression levels of endothelial NOS （eNOS） and neuronal NOS （nNOS） in the CC were markedly decreased in diabetic rats, long-term udenafil treatment improved the erectile function and increased cNOS expression compared with diabetic controls. These findings suggest that ED in DM is closely related to decreased cNOS expression in the CC and that udenafil has the ability to compensate for this pathological change by modulating cNOS expression. Udenafil also has an inhibitory role in cyclic guanosine monophosphate （cGMP） degradation.

关键词： cNOS diabetes mellitus erectile dysfunction udenafil

Recent advances in nanomaterials for high-performance Li–S batteries

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Journal of Energy Chemistry 2020年第8期29卷 86-106,I0004页

作者： James E.Knoop Seongki ahn Joint School of Nanoscience and Nanoengineering North Carolina Agricultural and Technical State UniversityGreensboroNC 27401USA Research Organization for Nano and Life Innovation Waseda University513WasedatsurumakichoShinjuku-kuTokyo 162-0041Japan

This article reviews nanotechnology as a practical solution for improving lithium-sulfur batteries. Lithiumsulfur batteries have been widely examined because sulfur has many advantageous properties such as a high crustal abundance, low environmental impact, low cost, high gravimetric(2600 W h kg-1) and volumetric(2800 W h L-1) energy densities, assuming complete conversion of sulfur to lithium sulfide(Li2S)upon lithiation. However, lithium-sulfur batteries have not yet reach commercialization due to demerits involving the formation of soluble lithium polysulfides(Li2Sn, n=3–8), low electrical conductivity, and low loading density of sulfur. These issues arise mainly due to the polysulfide shuttle phenomenon and the inherent insulating nature of sulfur. To overcome these issues, strategies have been pursued using nanotechnology applied to porous carbon nanocomposites, hollow one-dimensional carbon nanomaterials, graphene nanocomposites, and three-dimensional carbon nanostructured matrices. This paper aims to review various solutions pertaining to the role of nanotechnology in synthesizing nanoscale and nanostructured materials for advanced and high-performance lithium–sulfur batteries. Furthermore, we highlight perspective research directions for commercialization of lithium–sulfur batteries as a major power source for electric vehicles and large-scale electric energy storage.

关键词： Nanotechnology Lithium–sulfur batteries Carbon nanomaterials Nanocomposite sulfur 3D nanostructured materials

Intelligent SLAM Algorithm Fusing Low-Cost Sensors at Risk of Building Collapses

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Computers, Materials & Continua 2023年第1期74卷 1657-1671页

作者： Dahyeon Kim Junho ahn Computer Information Technology Korea National University of TransportationChungju27469Korea

When firefighters search inside a building that is at risk of collapse due to abandonment or disasters such as fire,they use old architectural drawings or a simple monitoring method involving a video device attached to a ***,using these methods,the disaster situation inside a building at risk of collapse is difficult to detect and ***,we investigate the generation of digital maps for a disaster site to accurately analyze internal *** this study,a robot combined with a low-cost camera and twodimensional light detection and ranging(2D-lidar)traverses across a floor to estimate the location of obstacles while drawing an internal map of the *** propose an algorithm that detects the floor and then determines the possibility of entry,tracks collapses,and detects obstacles by analyzing patterns on the *** robot’s location is estimated,and a digital map is created based on Hector simultaneous localization and mapping(SLAM).Subsequently,the positions of obstacles are estimated based on the range values detected by 2D-lidar,and the position of the obstacles are identified on the map using the map update method in semantic *** equipment are implemented using low-specification devices,and the experiments are conducted using a low-cost robot that affords near-real-time *** experiments are conducted in various actual internal environments of *** terms of obstacle detection performance,almost all obstacles are detected,and their positions identified on the map with a high accuracy of 89%.

关键词： Intelligence SLAM vision 2D-lidar low-cost algorithm

Generalized passivity-based chaos synchronization

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Applied Mathematics and Mechanics(English Edition) 2010年第8期31卷 1009-1018页

作者： C.K.ahn Faculty of the Division of Electronics and Control Engineering Wonkwang University

In this paper, a new passivity-based synchronization method for a general class of chaotic systems is proposed. Based on the Lyapunov theory and the linear matrix inequality （LMI） approach, the passivity-based controller is presented to make the synchronization error system not only passive but also asymptotically stable. The proposed controller can be obtained by solving a convex optimization problem represented by the LMI. Simulation studies for the Genesio-Tesi chaotic system and the Qi chaotic system are presented to demonstrate the effectiveness of the proposed scheme.

关键词： passivity-based synchronization linear matrix inequality (LMI) chaotic systems Lyapunov theory

Efficacy and safety of oral SK3530 for the treatment of erectile dysfunction in Korean men： a multicenter, randomized, doubleblind, placebo-controlled, fixed dose, parallel group clinical trial

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Asian Journal of Andrology 2008年第5期10卷 791-798页

作者： Jae-Seung Paick Hyung-Ki Choi Sae-Chul Kim Tai-Young ahn Je-jong Kim jong-Kwan Park Kwang-Sung Park Sung-Won Lee Sae-Woong Kim Kwanjin Park Hyonggi Jung Nam-Cheol Park Department of Urology Seoltl National University Hospital Seoul 110-744 Korea Department of Urology Yonsei University Yongdong Severance Hospital Seoul 135-720 Korea Department of Urology Chung-ang University Yongsan Hospital Seoul 140-757 Korea Department of Urology University of Ulsan Asan Medical Center Seoul 138-736 Korea Department of Urology Korea University Anam Hospital Seoul 136-705 Korea Department of Urology Chonbuk National University Hospital Jeonju 561-712 Korea Department of Urology Chonnam National University Hospital Gwangju 501-757 Korea Department of Urology Sungkyunkwan University Samsung Medical Center Seoul 135-710 Korea Department of Urology Catholic University St. Mary＇s Hospital Seoul 150-713 Korea Department of Urology Korea Cancer Center Hospital Seoul 139-706 Korea Department of Biostatistics Seokyeong University Seoul 136- 704 Korea Department of Urology Pusan National University Hospital Busan 602-739 Korea

Aim： To evaluate the efficacy and safety of SK3530, a newly developed type 5 phosphodiesterase inhibitor （PDE5I）, in Korean men with erectile dysfunction （ED）. Methods： A total of 119 patients were randomized at 10 centers in Korea to receive either SK3530 （50, 100, or 150 mg; n = 89） or placebo （n = 30） taken 1 h before anticipated sexual activity for an 8-week period. The patients were evaluated at baseline and 4 and 8 weeks after beginning therapy. Efficacy was assessed using the International Index of Erectile Function （IIEF）, Sexual Encounter Profile （SEP）, and the Global Assessment Question （GAQ）. Safety was analyzed by adverse events, laboratory values and vital signs. Results： At the end of the study, all the primary and secondary efficacy end-points were statistically significantly improved by SK3530 compared with placebo （P 〈 0.05）. Of the 89 patients in the treatment arm, 36 （42.3 %） achieved normal erectile function after treatment, including six patients with severe ED. Treatment-related adverse events occurred in 32 patients. The most common adverse events were flushing, headache, dizziness and eye redness （10.9%, 7.6%, 2.5% and 2.5%, respectively）, and most were mild. Only two patients discontinued treatment during the study period because of adverse events. Conclusion： The results of our phase Ⅱ study have confirmed the efficacy and safety of SK3530 in a broad population of men with ED of various etiologies and severity. The optimal doses in terms of efficacy and safety were determined to be 50 mg and 100 mg, respectively.

关键词： erectile dysfunction phosphodiesterase sildenafil citrate

COVID-19-activated SREBP2 disturbs cholesterol biosynthesis and leads to cytokine storm

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Signal Transduction and Targeted Therapy 2020年第1期5卷 910-920页

作者： Wonhwa Lee June Hong ahn Hee Ho Park Hong Nam Kim Hyelim Kim Youngbum Yoo Hyosoo Shin Kyung Soo Hong jong Geol Jang Chun Gwon Park Eun Young Choi jong-Sup Bae Young-Kyo Seo Aging Research Center Korea Research Institute of Bioscience and BiotechnologyDaejeon 34141Republic of Korea Division of Pulmonology and Allergy Department of Internal MedicineCollege of MedicineYeungnam University and Regional Center for Respiratory DiseasesYeungnam University Medical CenterDaegu 42415Republic of Korea Department of Biotechnology and Bioengineering Kangwon National UniversityChuncheonGangwon-do 24341Republic of Korea Center for BioMicrosystems Brain Science InstituteKorea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Division of Bio-Medical Science and Technology KIST SchoolKorea University of Science and TechnologySeoul 02792Republic of Korea College of Pharmacy Chungnam National UniversityDaejeon 34134Republic of Korea Department of Biomedical Engineering SKKU Institute for ConvergenceSungkyunkwan University(SKKU)SuwonRepublic of Korea Biomedical Institute for Convergence at SKKU(BICS) Sungkyunkwan University2066 Seobu-roJangan-guSuwon 16419Republic of Korea College of Pharmacy CMRIResearch Institute of Pharmaceutical SciencesBK21 Plus KNU Multi-Omics based Creative Drug Research TeamKyungpook National UniversityDaegu 41566Republic of Korea

Sterol regulatory element binding protein-2(SREBP-2)is activated by cytokines or pathogen,such as virus or bacteria,but its association with diminished cholesterol levels in COVID-19 patients is ***,we evaluated SREBP-2 activation in peripheral blood mononuclear cells of COVID-19 patients and verified the function of SREBP-2 in ***,we report the first observation of SREBP-2 C-terminal fragment in COVID-19 patients’blood and propose SREBP-2 C-terminal fragment as an indicator for determining *** confirmed that SREBP-2-induced cholesterol biosynthesis was suppressed by Sestrin-1 and PCSK9 expression,while the SREBP-2-induced inflammatory responses was upregulated in COVID-19 ICU *** an infectious disease mouse model,inhibitors of SREBP-2 and NF-κB suppressed cytokine storms caused by viral infection and prevented pulmonary *** results collectively suggest that SREBP-2 can serve as an indicator for severity diagnosis and therapeutic target for preventing cytokine storm and lung damage in severe COVID-19 patients.

关键词： cytokine diagnosis damage

Influence of process parameters on drilling characteristics of Al 1050 sheet with thickness of 0.2 mm using pulsed Nd:YAG laser

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中国有色金属学会会刊：英文版 2009年第B09期19卷 157-163页

作者： Dong-Gyu ahn Gwang-Won JUNG Department of Mechanical Engineering Chosun University

The object of this work is to investigate the influence of process parameters on drilling characteristics of an Al 1050 sheet with a thickness of 0.2 mm using a pulsed Nd:YAG laser through numerical analyses and experiments. By comparing the numerical analyses with the experiments, a proper numerical model was obtained. From the results of the numerical analyses and the experiments, the effects of process parameters on entrance diameters of drilled holes, shapes of the holes, taper angles of the holes and temperature distributions in the vicinity of the holes were examined quantitatively. In addition, the optimal drilling condition was estimated to improve the quality of the drilled holes.

关键词： YAG激光器工艺参数 Nd 脉冲井用厚度色基数值分析